yfz 450 jetting need help fast

[jsmith2232]

We installed on his 06 yfz 450 a gyrt pipe, header and airfilter, 45pilot, 165 main and stock needle and as it is now it idles great but when holding the throttle at mid it pops and flame comes out of the pipe and it appears that once it is revved to wot it sounds good. I think that the needle that came in the jet kit might need to be installed but at what clip setting? we are located in west michigan.

[GPracer2500]

The GYTR needle made a big improvement on the last YFZ I helped tune (similar settup to what you've got). I can't remember what clip position we settled on. I'd just start with it in the middle postion and go from there.

[jsmith2232]

I got it very close to being dialed in last night ended up with 45pilot 165main, 5th notch down one ncvq needle and 3 turns out on the fuel screw. everythings good except it still dies occasionally when stabbing the throttle off of an idle.

[GPracer2500]

Originally posted by jsmith2232
....it still dies occasionally when stabbing the throttle off of an idle.

Most likely the accelerator pump needs some fine tuning.